/*
 * @Author: your name
 * @Date: 2021-02-19 16:46:51
 * @LastEditTime: 2021-02-19 16:48:20
 * @LastEditors: Please set LastEditors
 * @Description: In User Settings Edit
 * @FilePath: \utils\base64\index.js
 */

 /**
 * @Description: base64加密
 * @author wuwx
 * @date 2020/10/28
*/
// https://juejin.cn/post/6844903698045370376 掘金
let keyStr = "ABCDEFGHIJKLMNOP" + "QRSTUVWXYZabcdef" + "ghijklmnopqrstuv"
+ "wxyz0123456789+/=";

let encode64 = function (input) {
var output = "";
var chr1, chr2, chr3 = "";
var enc1, enc2, enc3, enc4 = "";
var i = 0;
do {
  chr1 = input.charCodeAt(i++);
  chr2 = input.charCodeAt(i++);
  chr3 = input.charCodeAt(i++);
  enc1 = chr1 >> 2;
  enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
  enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
  enc4 = chr3 & 63;
  if (isNaN(chr2)) {
    enc3 = enc4 = 64;
  } else if (isNaN(chr3)) {
    enc4 = 64;
  }
  output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2)
    + keyStr.charAt(enc3) + keyStr.charAt(enc4);
  chr1 = chr2 = chr3 = "";
  enc1 = enc2 = enc3 = enc4 = "";
} while (i < input.length);
return output;
}
export default encode64;
